Audible signal device



Dec. 20, 1938. F. P. SCULLY El AL AUDIBLE SIGNAL DEVICE Filed Oct. 7,1936 2 Sheets-Sheet l Dec. 20, 1938. F.'P. SCULLY Er AL AUDIBLE SIGNALDEVICE Filed Oct. 7, 1936 2 Sheets-Sheet REISSUEB Patented Dec. 20, 1938UNITED STATES id Ug g.

PATENT OFFICE AUDIBLE SIGNAL DEVICE Frank P. Scully, Cambridge, andAlcide E. Mather, Auburndale, Mass., assignors to Scully Signal Company,Cambridge, Man, a corporation of Massachusetts Application October '2,1936, Serial No. 104.488 4Claims. (01. 110-109) a predetermined heightand thereafter discontinue upon attainment of the indicated level.

In pursuance of this and other objects, we have developed an audiblevent alarm for closed containers which consists essentially of a ventingconduit-from the container to atmosphere with an audible signal devicein series with the conduit. The conduit is essentially provided with anopen lower end, the. position of which J determines approximately thelevel at which the =audible signal is to be discontinued. Associatedwith the conduit are means which permit continued venting through thesignal device without causing audible operation thereof. This isaccomplished by varying the characteristics of the conduit from thelower end will cause actuationof the whistle. If, in addition," weprovide one or 35 more openings presumably in the side of the conduit inreasonable proximity to the whistle, then an air stream entering theconduit through these openings will not audibly sound the whistle. We donot attemptto account exactly for this mode of operation except that webelieve that an air stream entering the 'side' of the conduitor at anangle thereto or in such a manner as to unbalance a generally uniformflow of air throughout the cross-section of the conduit and 5 in thedirection of its length interferes sufficientlywith the functioning. ofthe whistle to avoid audiblesounding. In this connection, we have foundthat an orifice in theside of theconduit' located slightly below thewhistle and either circular, oval orrectangular, will accomplish thepurpose and that a reduction of the lower end of .the conduit'in half'with'an' upper opening lengthwise of'the conduit willalso accomplishthe'desired result. In all cases, the signal au'dibly sounds so long asan air stream can enter the conduit from the lower open end and passlengthwise thereof. In this case, the presence of the openings does notinterfere with the sounding of the signal. When the rising liquid levelblocks the open lower end, continued venting is compelled through sideorifices or their equivalent, and the signal fails to sound even thoughthe same essential volume of gas or vapor may be passing therethrough.This type of construction provides an extremely simple and eflicientmethod of audibly indicating the attainment of predetermined levels inall cases where venting from the closed container may be satisfactorilyaccomplished by the single vent in which the signal is located or, inother words, where the orifice of the signal itself creates sufflcientventing capacity. 'Inthose cases where the signal orifice itself isinsuflicient or cannot practically be made large enough to besufficient,

then continued venting after the predetermined 2o level has been reachedmustbe accomplished by by-passing gases or vapors in some fashion aboutthe signal device.

In the accompanying drawings illustrating the preferred form of theinvention, Fig. 1 illustrates a cross-sectional elevation of an audibleventing device-introduced into the filler pipe of a motor vehicle fueltank; Fig. 2 is a similar cross-sectional view with a different form offiller pipe; Fig. 3 is a third type in which the filler and vent areseparate; Figs. 4,- 5 and 6 are sections in elevation illustratingalternative methods of varying theair stream to provide operation of theaudible signal; and Figs. 7, 8 and 9 are end views .respectively of theconstructions shown in each the usual fuel tank of a motor vehicle isindi-- cated at It and is provided with a fuel pipe I! entering the sideof the tank adjacent the top. This fuel pi-pe extends outwardly into aposition conveniently accessible to the operator. It may be attached tothe side of the tank through a sleeve coupling ll welded to the side ofthe tank and threadedly connected with a complementary member I, the twomembers of the coupling serving to clamp between them an outturnedflange I. on the fuel pipe, together with suitable packing rings 20. Inorder to determine when the contents of the fuel tankhave reached a topredetermined level, without resorting to gages or similardevices, weprovide a vent pipe 22. within the fuel pipe and having a downturned end24 within the tank which, as shown in Fig. 1, terminates atapproximately the level of the bottom of the feed pipe. This downturnedopen end 24 predetermines the liquid level at which audible indicationceases, as will be hereinafter more fully described. As indicated, thevent is provided above the open end' with an oriflced whistle indicatedat 26 and openings 28 in the sideof the vent and in proximity to thewhistle. The entering passage through the fuel pipe I2 is partiallyrestricted by an inclined baille 30 which tends to divert incomingliquidfrom the lower end of the vent pipe and also restrict the passage in thefeed pipe to insure substantially against venting of gas or airtherethrough.

Fig. 2 illustrates a slightly modified form of construction in which thetank I is provided with an inclined feed pipe 32 entering the top of thetank through a fitting 34. The vent pipe 36 extends lengthwise of thefeed pipe and projects at its lowerend into the tank a predetermineddistance, the open lower end 38 of the vent serving to indicate apredetermined liquid level as in'the case of the construction shown inFig. 1. A baflie 40 extends across the feed pipe to partially restrictthe entering passage and insure escape through the vent pipe, aspreviously described.

In the construction shown in Fig. 3, the tank It) is provided with'afeed pipe'42 entering the top thereof through a connection 44. This feedpipe extends through the tank to a-point adjacent the bottom so that thelower end of the feed pipe is always trapped against escape ofgas or airso long as .fuel remains in the tank. A separate vent 46 enters the tankand has an open lower end located at 48. Thisvent, similar to thoseshown in Figs. 1 and 2, is provided with an audible whistle 26 and withside orifices 52.

All of the constructions shown in Figs. 1 to 3 inclusive have a commonmode of operation, namely, the liquid delivered to the tank through thefeed pipe causes escape of air and gas through the open lower end of thevent as the liquid level within the tank rises. This escaping stream ofair passing through the vent pipe from the open lower end causesactuation of the audible whistle which continues until the rising liquidlevel contacts with and blocks the open lower end of the vent pipeagainst further escape of gas or air therethrough. Continued delivery ofliquid with a consequent rising level will cause venting of air or gasthrough the side openings 28, as shown in Fig. 1, this air also passingthrough the audible whistle. Although these openings provide forcontinued venting and avoid excessive pressure increase if the tank isfilled beyond the lower ehd of the vent pipe, nevertheless no actuationof the audible signal takes place after the lower end of the vent pipehas been blocked. Neither do these openings, if properly constructed,interfere with the actuation of the audible signal on account of the airstream entering through the lower end of the vent.

Illustrated in Figs. 4 to 9, inclusive, are a series of alternativeconstructions, all of which serve as combined vents'and audible signaldevices to permit continuous venting through the same conduit so long asfilling continues, but to discontinue audiblesignalling when the fillinglevel reaches the open lower end of the vent pipe. Indicated'in Figs. 4and '7, is an enlarged viewof the construction shown in -Figs. 1 to 3,inclusive. In this view, the lower end of the vent pipe is indicated at24 and is provided with an orificed whistle 26 of conventional formfitting closely in the vent and with supplementary vent openings 28 inthe side of the vent pipe below the whistle and in proximity thereto. Solong as the air stream enters the vent pipe through the open lower end50, actuation of the whistle takes place. When this open lower end isblocked by rising liquid, continued venting may take place through oneor more openings 28 without, however, causing actuation of the signal ifthe openings are located'in sufficiently close proximity to the whistledevice to avoid straightening out of the air stream before it reachesthe whistle. In addition, the supplementary vent openings should besmaller in their combined area than the area available for ventingthrough the open lower end in order that the venting of air through theopen lower end until this portion is trapped shall constitute the pathof least resistance for the flow of air theret-h-rough.

In Figs. and 8 is illustrated a similar but not identical constructionwhich has an equivalent mode of operation. In this construction, thevent pipe 24 is provided with the same whistle 26 and the open lower end50 but the circular or round vent openings have substituted therefor anelongated and comparatively narrow slot 52 in the side of the vent tubebelow the whistle.

In Figs. 6 and 9 is illustrated a third form in which a vent tube 54 isreduced at its lower end 56 through the employment of a lengthwisepartition 58 extending transversely of the tube, as indicated in Fig. 9.This partition extends into proximity to the whistle 26 and at theopposite side thereof is provided a supplemental vent 60 produced bycutting away a portion of the tube, as will be clearly evident. Withthis construction, so long as the open lower end. of the vent is abovethe liquid level and gas can be freely vented through the tube on bothsides of the partition, actuation of the whistle is produced. When theopen lower end is blocked, however, further venting would occur throughthe supplementary vent 50 without, however, actuating the whistle. Although the flow produced by this device may be somewhat difierent fromthat produced by the openings in the wall of the tube, nevertheless theresultant effect, namely, sounding of the audible signal with cessationwhen the lower end of the tube is blocked, is the same in all cases.

The foregoing constructions illustrate in part the variations which maybe-made in the actual devices without departing from the scope of theinvention. As stated previously, althoughl the exact theory upon whichthese constructions operate 1 is not fully and completely understood,nevertheless it is quite evident that an air stream entering the tubebelow the whistle through an orifice of ample capacity willsatisfactorily actuate the whistle and that additional openings prethewhistle to avoid operation as the utilization of supplementary openingsin a long tube with the openings sufficiently removed from the whistleby a length of tube would permit smoothing out of the air stream andwould defeat the result sought for. Generally speaking, supplementaryopenings or passages located in sufllciently close proximity to thewhistle to cause turbulence oi the air stream impinging on the whistlewill avoid sounding thereof and these same openings or pasentering inthis manner.

What is claimed is:

l. The combination with a closed container, of a conduit extending intothe container below the top thereof andopen at its lower end, an audiblesignal in series with the conduit and normally actuated by a stream ofgas or vapor entering the conduit from the open end when the risingliquid. level is below the lowermost portion of the conduit, andmeans-associated with the conduit so constructed and arranged relativethereto and to the audible signal as to vary the characteristics of theair stream, after entrance to the lowermost portion oi the conduit hasbeen sealed by rising liquid level, to avoid actuation of said signalwhile still permitting continued virliting 01' gas or vapor through theaudible sign 2. The combination with a liquidtank, of a conduit havingan open lower end below the top 01 the tank and serving as a ventwithout the tank, an audible signal in serieswith the conduit andnormally actuated bya stream of gas or vapor entering the conduitthrough the open lower end when the rising liquid level is. below thisend of the conduit, and a supplementary open-- ingdelivering air or gasat the sideoi the conduit at such a location relative to the signal andin such a manner, when the open lower end is sealed and ventingcontinues through the conduit and the signal, as to avoid actuation ofthe signal.

3. The combination with a liquid tank, of a conduit having an open lowerend below the top of the tank and serving as a vent without the tank, anaudible signalvin series with the conduit and normally actuated by astream of gas or vapor entering the conduit through the openlower endwhen'the rising liquid level is below'this end of the conduit, and asupplementary opening in the side of the conduit in such close proximityto the signal and of less area than the opening at the lower end of theconduit and so constructed as to vent air or gas through the signaldevice after the lower end of the conduit has been sealed in such aturbulent manner as to avoid actuation of the signal device.

4. The combination with a liquid tank. of a conduit having an 'openlower end below the top of the tank and serving as a vent without thetank, an audible signal in series with the conduit and normally actuatedby a stream of gas or vapor entering the conduit through the open lowerend when the rising liquid level is below this end oi the conduit, and acircumierentially extending series of openings formed in the side' 01'the conduit 'in such close proximity to the signal, and being of lesstotal area than the opening at the lower end. of the conduit, to ventair or gas through the signal device after the lower end of the conduithas been sealed in such a turbulent manner as to avoid actuation of thesignal device.

